Space properties Buttons Lost!

Hi guys
I’ve lost my properties buttons in a project i.e. render,world,materials, particles etc. must have pressed the wrong key sometime but I cant find any reference on the internet. any suggestions?

So little information.

Do you see anything ? Some buttons, no button, the properties panel at all, have you anything selected ?

Have you just hidden the header, is there a + symbol where the header should.

Toss us a bone with at the very minimum a screenshot or blend file !

not sure if I got this right but screenshot should be attached.

just answered my own question!
Ctrl+left arrow brings back the properties and scene window

Or see the big ‘Back to Previous’ button at the top of the window to go out of Full Screen mode